The present invention relates to a female terminal fitting for a board having a stress relaxation portion.
Referring to FIG. 7A, in a female terminal fitting 101 disclosed in JP-A-3-11566, a box-shaped female electrical contact portion 103 is formed on the front side of a bottom plate 102. Further, a fixed portion 104 is formed on the rear side of the bottom plate 102. A U-shaped supporting portion 105 which rises from both right and left sides is formed at a rear end of the bottom plate 102. An upper plate 107 is formed continuously with a pair of connecting pieces 106 which become both side walls of the supporting portion 105. A fixing flexible plate 108 is continuously formed toward the female electrical contact portion 103 from the plate 107. The fixing flexible plate 108 is formed so as to face a rear portion 109 of the bottom plate 102. A locking hole 110 is formed in the fixing flexible plate 108. A curved resilient piece 111 which is folded back in a U-shape is formed continuously with the portion of the fixing flexible plate 108 on the side of the female electrical contact portion 103. A slanting engagement and guide portion 112, a part 113 continuous with the slanting engagement and guide portion 112, and a slanting resilient 114 are formed in the curved resilient piece 111. A protruding portion 115 for soldering is formed continuously with the slanting resilient portion 114.
Referring to FIG. 7B, a connector housing 116 has a terminal receiving chamber 117 which receives the female terminal fitting 101. The terminal receiving chamber 117 is formed such that a male terminal insertion hole 118 is located on the left of the drawing, and a female terminal fitting insertion hole 119 is located on the right of the drawing. A locking projection 120 which is hooked to the locking hole 110 of the female terminal fitting 101 is formed in the terminal receiving chamber 117.
In the above configuration, when the female terminal fitting 101 is inserted into the terminal receiving chamber 117 via the female terminal fitting insertion hole 119, the front face of the female electrical contact portion 103 of the female terminal fitting 101 abuts on the inner surface of the male terminal fitting insertion hole 118, and the locking hole 110 of the female terminal fitting 101 is locked by the locking projection 120. Thereby, assembling of the connector 121 is completed. Thereafter, when the protruding portion 115 for soldering of the female terminal fitting 101 is inserted into a printed wiring board 122, and soldering 123 is then performed, the connector 121 is fixed to printed wiring board 122, which allows connection with a mating connector.
Even if an axial positional deviation is caused between the connector 121 and the male terminal fitting of the mating connector, the curved resilient piece 111 of the female terminal fitting 101 is adapted to be able to resiliently deform in an up-down direction or a right-left direction (in the direction of the central axis of the female terminal fitting 101) of the FIG. 7B, and thereby to absorb the positional deviation (the female terminal fitting 101 has a structure which hardly deforms in a direction perpendicular to the sheet plane of FIG. 7B). The curved resilient piece 111 is formed so as to function as a stress relaxation portion in the female terminal fitting 101.
Meanwhile, the above conventional female terminal fitting 101 has a structure which hardly deforms in a direction perpendicular to the sheet plane of FIG. 7B. Therefore, if the male terminal fitting of the mating connector haven been obliquely inserted, a contact portion (spring portion 124) of the female terminal fitting 101 is excessively bent by the male terminal fitting. This bending causes permanent deformation. As a result, there is a problem in that stable contact cannot be secured. Further, on the side of the connector 121, there is also a problem in that the female terminal fitting 101 may be curved and deformed by the movement of the mating connector.
In addition, in the above conventional female terminal fitting 101, there is also a problem in which, even if dimensional control by image processing is attempted in order control the gap between the inner surface of the female electrical contact portion 103, and the spring portion 124, this control cannot be executed. This is because, even if a camera 125 is set in front of the female electrical contact portion 103, a light source 126 is set behind the protruding portion 115 for soldering, and then light 127 is emitted forward from the light source 126, the light 127 may be shielded by the curved resilient piece 111, and the light 127 does not reach the gap between the inner surface of the female electrical contact portion 103, and the spring portion 124, and consequently, photographing by the camera 125 cannot be performed. Due to such a problem, it becomes impossible to perform high-precision dimensional control. As a result, the reliability related to electrical contact may be degraded.
Since the above conventional connector housing 116 has the locking projection 120 which is hooked to the locking hole 110 of the female terminal fitting 101, there is a problem in that the die structure for portions of the terminal receiving chambers 117 may become complicated.